In recent years, scanning probe microscopy (SPM) techniques have been widely used for nanolithography applications. The scanning probe in an SPM instrument can be used to modify a surface with nanoscale resolution through direct or indirect approaches. Direct scanning probe lithography (SPL) methods, including dip pen nanolithography (DPN) and scanning probe contact printing (SPCP), allow deposition of a variety of chemical and biological materials with high resolution and multi-layer registration capability. DPN uses a sharp, coated atomic force microscope (AFM) tip to transfer molecules onto a solid surface. It has been used to generate images with feature sizes smaller than 100 nanometers (nm). SPCP uses a probe having an elastomeric tip to print images on a surface. Typically, an ink is first absorbed into the elastomeric tip, and each contact of the tip on the surface transfers the ink, creating a pixel print. Images can be generated by SPCP in a dot-matrix manner.
In conventional probe-based nanolithography, a single probe typically is used for both writing and reading. This creates a risk of cross-contamination during use. Although it is possible to switch the probes between writing and reading runs, this practice can be inefficient due to the time required to register the writing and reading probes with nanometer resolution. For future nanotechnology applications, it is desirable to perform a wide variety of different lithography and microscopy operations without having to switch probes and perform multiple registrations.